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survivors generally have an increased risk of new tumor
formation.
Proffered Papers: Clinical 8: Adult and paediatric CNS
malignancies
OC-0345
Patterns of failure after radiotherapy in pediatric
ependymoma: correlation with dose parameters
F. Tensaouti
1
UMR 825 Inserm / Université Toulouse Iii - Paul Sabatier,
Research, Toulouse, France
1
, A. Ducassou
2
, S. Bolle
3
, X. Muracciole
4
, B.
Coche-dequeant
5
, L. Claude
6
, S. Supiot
7
, C. Alapetite
8
, V.
Bernier
9
, A. Huchet
10
, C. Kerr
11
, E. Le Prise
12
, G. Truc
13
, E.
Regnier
14
, S. Chapet
15
, A. Lisbona
7
, G. Hangard
2
, A. Laprie
2
2
Institut Claudius Regaud Toulouse- Iuct Oncopole,
Radiotherapy, Toulouse, France
3
Institut Gustave Roussy- Villejuif, Radiotherapy, Paris,
France
4
CHU La Timone, Radiotherapy, Marseille, France
5
Centre Oscar Lambret, Radiotherapy, Lille, France
6
Centre Léon Bérard, Radiotherapy, Lyon, France
7
Institut De Cancérologie De L’ouest, Radiotherapy, Nantes,
France
8
Institut Curie, Radiotherapy, Paris, France
9
Institut De Cancérologie De Lorraine- Alexis Vautrin,
Radiotherapy, Nancy, France
10
CHU Bordeaux, Radiotherapy, Bordeaux, France
11
Institut Du Cancer De Montpellier, Radiotherapy,
Montpellier, France
12
Centre Eugène Marquis, Radiotherapy, Rennes, France
13
Centre Georges François Leclerc, Radiotherapy, Dijon,
France
14
Institut Jean Godinot, Radiotherapy, Reims, France
15
CHU Tours, Radiotherapy, Tours, France
Purpose or Objective:
The aim of this study was to
investigate the patterns of failure after radiotherapy for
pediatric intracranial ependymoma and their correlation to
dose parameters.
Material and Methods:
Between 2000 and 2013, 206 patients
with intracranial ependymoma were treated in the 13 french
reference pediatric radiotherapy centers . The magnetic
resonance imaging obtained at recurrence were registered
with the original planning CT for topographic analysis of the
patterns failure. Clinical target volume (CTV) and planning
target volume (PTV) margins were extracted ; several
dosimetric quality indices were derived from Dose Volume
Histogram (DVH) to compare relapse with no-relapse patient.
Results:
With a median follow-up of 44.81 months (95% CI
[36.80; 56.51]), 85 (41.3%) patients presented with
recurrence. The topographic analysis of patterns of failure
showed 50 (58.8%) patients with local recurrence in the
radiation field (LF), 6 (4.1%) in the edge of field (EFG), 6
(7.1%) were loco-regional outside the field (LRF), 8 (9.4%) in
spine (SF), 5 supratentorial (SUF) and 10 (11.8%) local and
distant (LDF). The median prescription dose was respectively:
55.8 Gy [50.4; 60] in LF, 54 Gy [48.6; 59.4] in EF, 56.7 Gy
[50.4; 60] in LRF, 54 Gy [50.4; 59.4] in LDF, 59.4 Gy [48.6-
59.4] in SUF and 56.7Gy [54; 60] in SF. The median PTV
margins was 0.5 mm [0.3; 1]. The median Coverage index and
The Target Coverage index of the PTV were both lower in the
relapse group as they were respectively 0.97 and 94.8% in the
relapse group compared with 0.98 and 95.99% in the no-
relapse group. The median Homogeneity index was 0.097 in
the relapse group versus 0.091 in the no-relapse group. The
median volume of relapse was 1.29 cc [0.11; 27] in the LF
group, with a median dose of 58.81 Gy [50.86; 61.38].
Conclusion:
In patients with intracranial ependymoma, local
failure in the tumor bed was the major pattern of failure.
The preliminary results showed that all dosimetric indices on
the PTV were worse in the relapse group. Improving the
coverage of target volume may be an effective way to reduce
the local failures. Thus a complementary correlation of
relapse patterns with dose parameters to PTV and organs at
risks and the irradiation techniques is under statistical
analysis and final results will be presented at the meeting.
OC-0346
Pediatric diffuse intrinsic pontine glioma re-irradiation:
better survival and better time
L. Gandola
1
Fondazione IRCCS Istituto Nazionale dei Tumori, Radiation
Oncology- Pediatric Radiotherapy Unit, Milan, Italy
1
, E. Pecori
1
, V. Biassoni
2
, B. Diletto
1
, E.
Schiavello
2
, S. Meroni
3
, F. Spreafico
2
, E. Pignoli
3
, M.
Massimino
2
2
Fondazione IRCCS Istituto Nazionale dei Tumori, Pediatric
Oncology, Milan, Italy
3
Fondazione IRCCS Istituto Nazionale dei Tumori, Medical
Physics, Milan, Italy
Purpose or Objective:
Since 2009 we launched a strategy for
children with centrally reviewed MRI diagnosis of diffuse
intrinsic pontine glioma (DIPG) implying the intravenous
administration of vinorelbine with nimotuzumab –an anti-
EGFR monoclonal antibody- weekly, for a total of 12 weeks,
during radiotherapy delivery of 54 Gy, 1.8 Gy/fraction daily.
After radiotherapy completion, vinorelbine and nimotuzumab
were administered any other week until tumor progression or
for a total of two years. In the attempt to improve survival
and quality of life of our children, a protocol amendment in
July 2011 introduced re-irradiation at relapse/progression.
Material and Methods:
Local re-irradiation consisted of 19.8
Gy, fractionated over 11 days. A 3DCRT with 5-6 coplanar
beams was adopted with a beam geometry possibly not
overlapping that of the first line irradiation; the most
demanding planning issue of re-irradiation was to meet optic
chiasm dose constraints. Three additional children were re-
irradiated to distant sites of relapse, spine (2) or ventricular
system at doses of 36 Gy or 54 Gy respectively.
Results:
Of the 39 patients treated from 8/2009, 28 had local
(23) or disseminated (5) progression and 18 were given local
(15) or distant (3) relapse re-irradiation at a median of 8
months after first radiotherapy (2.5-19 months). Reasons for
not re-irradiating the other 10 children were: progression
before July 2011 (4), parents refusal (4), too poor Lansky
status (2); median PFS and progression site were not
different in the two subgroups. Survival after re-irradiation
lasted between two weeks and 14 months, median 6 months,
and determined a statistically difference in median OS
between the two groups of re-irradiated or not children,
being 16 and 12 months, respectively (P=0.004). In 16
radiologically evaluated patients, re-irradiation induced:
reduction of tumor volume in 8, stable volume in 3 while 5
had progression; 13 had symptom amelioration and 12 steroid
suspension. Volume reductions were obtained in 7/8 children
that have shown the same response after first line irradiation
while one was obtained after stable disease in first line
treatment. No adverse event was reported and all children
were re-irradiated as outpatients .
Conclusion:
Re-irradiation after relapse/progression
represented a significant benefit for both OS and quality of
life of children with DIPG with symptom amelioration in
13/18. This option is worth to be offered also in case of
disseminated progression.
Partially supported by Associazione Italiana per la Ricerca sul
Cancro (AIRC)
OC-0347
Outcome and prognosticators in adult patients with
medulloblastoma: a Rare Cancer Network study
B. Atalar
11
Acıbadem University, Department of Radiation Oncology,
Istanbul, Turkey
1
, M. Ozsahin
2
, J. Call
3
, A. Napieralska
4
, S. Kamer
5
,
V. Salvador
6
, P. Erpolat
7
, L. Negretti
2
, Y.L. Ramstad
8
, C.
Onal
9
, S. Akyurek
10
, G. Ugurluer
1
, B. Baumert
11,12
, S. Servagi-
Vernat
13
, R.C. Miller
14
, E. Ozyar
1
, T. Sio
15
2
Centre Hospitalier Universitaire Vaudois, Department of
Radiation Oncology, Lausanne, Switzerland